| 摘要 |
PURPOSE:To recognize the condition of the convection of a silicon melt overall by producing the spherical tracer for observing the melt, which tracer consists a high melting metal coated with plural coating layers around the metal and has the sphericity of a specific value. CONSTITUTION:This tracer is formed by using the high melting metal as a nucleus and applying quartz glass as the coating layer on the inner side and a material having good wettability as the coating layer of the outormost side in order to assure the wettability with the melt on this metal. The spherical tracer having <=50mum sphericity after the application is used for such tracer. The material having the good wettability is, therefore, sprayed on the material which is made of the metal as its nucleus, is coated with the quartz glass and is worked to a spherical shape while gas is injected to suspend the material. The tracer is rotated by the pressure of the gas in this way and is uniformly coated with the material. The supply of a large quantity at a time is possible as well. The inside of the melt is observed by using plural pieces of the tracers having the high sphericity of <=50mum and, therefore, the follow up of the tracers to the convection of the melt is possible. |
